Creatine increases how long you can maintain an intense effort. For example when lifing heavy weights you'll be ablet maintain peak performance for 3-5 seconds more, which should give you 1 or 2 more reps in your maximum rep set with the 5/3/1 program. You still have to do those reps for creatine to help you in that regard.
There is also evidence that creatine can increase satellite cell activation which helps repair damaged muscle/grow muscle.
It affect different persons to different extent though. Those who consume a lot of meat do not seem to benefit as much since their diet is already fairly high in creatine.